SQL:将变量值与多个列匹配并选择匹配的列名

Question

我想获取电话号码匹配的记录。共有 3 列保存电话号码。工作、家庭和手机。我正在编写一个查询来检查电话号码是否与 3 列中的任何一列匹配。

declare @phNo nvarchar(15) = 'xxxxxxxxxx'

select HomePhone, cellphone, workphone, * 
from Contact_Table 
where @phNo in (HomePhone, cellphone, workphone)

此查询工作正常，但我还想要与电话号码匹配的列名称。如何获取匹配列的名称？

例如，如果电话号码与“homehpone”匹配，则结果集应返回“homephone”

Answer 1

这可以通过 CASE 来完成:

DECLARE @phNo NVARCHAR(15) = 'xxxxxxxxxx';

SELECT homephone,cellphone,workphone, *,
       CASE WHEN @phNo = homephone THEN 'homephone'
            WHEN @phNo = cellphone then 'cellphone'
            WHEN @phNo = workphone THEN 'workphone'
            END AS PhoneMatch
FROM Contact_Table
WHERE @phNo IN (HomePhone,cellphone,workphone);